Newly released documents from the FBI’s criminal investigation into Hillary Clinton’s mishandling of highly classified materials highlight a “serious, but flawed investigation hindered by a lack of cooperation,” according to a new report.

One document shows that one of Clinton’s private attorneys, Katherine Turner, had agreed to turn over one of Clinton’s non-secure Apple iPads and two of her BlackBerrys to the FBI.

However, neither smartphone had SIM cards or Secure Digital (SD) cards, the report said. A total of 13 mobile devices identified by the FBI as potentially using clintonemail.com addresses were never located by Clinton’s lawyers, according to government watchdog group Judicial Watch’s President Tom Fitton.

Some of those devices were pounded with hammers after Clinton’s homebrew servers went down or after news that Clinton aide Sidney Blumenthal’s email had been hacked, the report said.